[14.09] Detection of Granulation in Procyon

The WIRE satellite has observed the F-type star Procyon for
two periods during 1999 and 2000. The two data sets consist
of time series of 10 days length with a cadence of 0.5
seconds and a duty cycle of 15 than the Sun and thus [the
photometric signal arising from] granulation is expected to
have higher amplitude. We have used the two WIRE data sets
to put an upper limit on the granulation and find this to be
close to a factor of two times the amplitude seen in the
Sun. This limit is lower than the factor [of] five proposed
by observations with the Canadian MOST mission (Matthews et
al. 2004). Due to the rather low duty cycle in the WIRE data
set we are not able to confirm the oscillations seen in
Procyon from radial velocity measurements (Martic et al.
2004).